Last July, Florida Highway Patrol Trooper Marcos Diaz was having dinner at Subway at Mile Marker 103 with a Keys deputy when they got a call about a man in distress.

Rolando Riveron-Martinez of Hialeah had been out fishing in small paddleboat with a friend near Mile Marker 109, ocean side, when the boat overturned. By the time Diaz made it to the scene, Riveron-Martinez was holding onto a small cooler.

"I made the decision to just start stripping my clothes off, and being a prior Marine, I'm a confident swimmer," Diaz said.

Riveron-Martinez had already been in deep water some 200 yards offshore for at least 20 minutes when Diaz removed his gun belt, bulletproof vest, shirt and boots while an arriving paramedics provided him with a floating backboard.

"I used their backboard like a surfboard and paddled out there," Diaz said. "I could hear the gentleman screaming in Spanish that he was already really tired and having trouble keeping his head above water."

What Diaz didn't know was that Riveron-Martinez had hundreds of yards of fishing line wrapped around his legs and ankles. Diaz estimated that he had already been trying to tread water for 20 minutes by the time rescuers arrived.

It would take Diaz another 15 minutes to reach Riveron-Martinez in rough seas and by that time, about 7:30 p.m., the sun was setting. Soon, both men were enveloped in darkness, making it hard to find their bearings as they struggled to free Riveron-Martinez from the fishing line.

"I handed him my knife, but we were both exhausted," Diaz said. "He had been in the water nearly 40 minutes by that time. He was going under. There was a good chop out there and I was swimming full speed at the last 20 feet."

By chance, Riveron-Martinez had a head lamp that Diaz used to wave to Coast Guard Station Islamorada crews looking for the men.

"By the time we got in the boat, his feet were bone white from the fishing line cutting off circulation," Diaz said.